I don't understand what is `hours` in this example

I'm learning how to use conditional clauses in sqlite language. On SO I found that link: http://ift.tt/1Lk7HFK, in an answer/comment (I didn't mark the question, I closed my browser too fast, sorry for that).

I write (in a more readable way. With sqlite I miss the {} so do not hesitate (if you want it) to rewrite it with {} just to help me to clearly see the blocks) here the part wich interest me :

SELECT
  tbl_hours.week_number 'Week #'

, tbl_employee.employee_id 'Id Number'

, tbl_employee.first_name||' ' ||tbl_employee.last_name 'Name'

, hours /*1*/

, CASE WHEN (hours/*2*/>40) 
  THEN hours-40 ELSE 0 END 
    AS overtime 
    FROM tbl_employee, tbl_Hours 
    WHERE tbl_employee.employee_id = tbl_hours.employee_id 
    ORDER BY tbl_hours.week_number,tbl_employee.employee_id; 

there is hours but actualy I don't know what is it. That seems to be a variable, but how sqlite considere /*1*/ and /*2*/ for each employee ?

I add the result (still from the same link)

WEEK #  ID NUMBER    NAME              HOURS        OVERTIME    
------- ------------ ----------------- ------------ ---------   
1       50           JONATHAN SMITH     37.5        0   
1       60           GERALD MARSHAL     40.25       0.25    
2       50           JONATHAN SMITH     28.5        0   
2       60           GERALD MARSHAL     40.25       0.25    
3       50           JONATHAN SMITH     41.5        1.5 
3       60           GERALD MARSHAL     41.5        1.5 
4       50           JONATHAN SMITH     40          0   
4       60           GERALD MARSHAL     47.75       7.75    
5       50           JONATHAN SMITH     40          0   
5       60           GERALD MARSHAL     40          0